Snowmobile allowances in Yellowstone change again

The National Park Service says new pollution-control and noise-abatement technology will be sufficient to counteract an increased number of snowmobiles and other snow machines allowed into Yellowstone National Park this winter.

The agency announced it latest proposal last week.

The park service's position on snowmobiles in Yellowstone has changed repeatedly over the past decade.

The agency endorses allowing a maximum of 480 snowmobiles plus 60 snow coaches per day into Yellowstone.

The number of snow coaches, meaning passenger vans retrofitted with skis and tracks, could double in the future if they meet noise and pollution standards. The average number of snowmobiles per day couldn't exceed 342 over a winter season.

The Park Service has set daily limits of 318 snowmobiles and 78 snow coaches in recent years. Wenk said the park's daily average was 190 snowmobiles and about 35 snow coaches last winter.